Proceedings ArticleDOI
On Deriving Good LDPC Convolutional Codes from QC LDPC Block Codes
Ali Emre Pusane,Roxana Smarandache,Pascal O. Vontobel,Daniel J. Costello +3 more
- pp 1221-1225
TLDR
Results taken together lead to improved BER performance in the low-to-moderate SNR region, where the decoding behavior is influenced by the complete pseudo-codeword spectra and by the Tanner graph cycle histogram, with the time-varying convolutional codes outperforming both the underlying QC block codes and their time-invariant Convolutional counterparts.Abstract:
In this paper we study the iterative decoding behavior of time-invariant and time-varying LDPC convolutional codes derived by unwrapping QC LDPC block codes. In particular, for a time-varying LDPC convolutional code, we show that the minimum pseudo-weight of the convolutional code is at least as large as the minimum pseudo-weight of the underlying QC code. We also prove that the unwrapped convolutional codes have fewer short cycles than the QC codes. These results taken together lead to improved BER performance in the low-to-moderate SNR region, where the decoding behavior is influenced by the complete pseudo-codeword spectra and by the Tanner graph cycle histogram, with the time-varying convolutional codes outperforming both the underlying QC block codes and their time-invariant convolutional counterparts.read more
Citations
More filters
Journal ArticleDOI
Deriving Good LDPC Convolutional Codes from LDPC Block Codes
TL;DR: In this paper, several graph-cover-based methods for deriving families of time-invariant and time-varying LDPC convolutional codes from LDPC block codes are discussed.
Journal ArticleDOI
Eliminating Trapping Sets in Low-Density Parity-Check Codes by Using Tanner Graph Covers
TL;DR: A method for improving the performance of low-density parity-check (LDPC) codes in the high SNR (error floor) region is presented and is universal, as it can be applied to any LDPC code/channel/decoding algorithm and improves performance at the expense of increasing the code length.
Patent
Low-density parity check convolution code (ldpc-cc) encoder and ldpc-cc decoder
TL;DR: In this article, an LDPC-CC (Low-Density Parity-Check Convolution Codes) encoder and decoder is proposed, which performs an error correction encoding and decoding while reducing the amount of a termination sequence required for encoding/decoding.
Patent
Encoding method, encoder, and decoder
TL;DR: In this paper, a low-density parity check convolution code (LDPC-CC) is made, and a signal sequence is sent after subjected to an error-correcting encodement using the low density parity check Convolution code.
Patent
Transmission method and transmission apparatus
TL;DR: In this paper, the authors proposed a modulation scheme to improve the data transmission efficiency when transmitting data using the plurality of antennas, where a base station apparatus does not change the transmission method during data transmission and only changes only the modulation scheme.
References
More filters
Journal ArticleDOI
Time-varying periodic convolutional codes with low-density parity-check matrix
TL;DR: A class of convolutional codes defined by a low-density parity-check matrix and an iterative algorithm for decoding these codes is presented, showing that for the rate R=1/2 binary codes, the performance is substantially better than for ordinary convolutionian codes with the same decoding complexity per information bit.
Journal ArticleDOI
LDPC block and convolutional codes based on circulant matrices
TL;DR: A class of algebraically structured quasi-cyclic low-density parity-check (LDPC) codes and their convolutional counterparts is presented and bounds on the girth and minimum distance of the codes are found, and several possible encoding techniques are described.
Journal ArticleDOI
Using linear programming to Decode Binary linear codes
TL;DR: The definition of a pseudocodeword unifies other such notions known for iterative algorithms, including "stopping sets," "irreducible closed walks," "trellis cycles," "deviation sets," and "graph covers," which is a lower bound on the classical distance.
Journal ArticleDOI
Selective avoidance of cycles in irregular LDPC code construction
TL;DR: A Viterbi-like algorithm is proposed that selectively avoids small cycle clusters that are isolated from the rest of the graph and yields codes with error floors that are orders of magnitude below those of random codes with very small degradation in capacity-approaching capability.
Posted Content
Graph-Cover Decoding and Finite-Length Analysis of Message-Passing Iterative Decoding of LDPC Codes
Pascal O. Vontobel,Ralf Koetter +1 more
TL;DR: In this article, the authors introduce the concept of graph-cover decoding, which is a theoretical tool that can be used to show connections between linear programming decoding and message-passing iterative decoding.